Ladder web



ca. F. FRENCH 2,238,465

HADDER WEB Filedllay 10,1939 '2 Sheets-Sheet 1 April 15, 1941.

INVENTOR. 6:020: [fire-Arr ATTORNEY.

April 15, 1941. a. F FRENCH LADDER WEB Filed May 10, 1939 2 Sheets-Sheet2,

mm \m ATTORNEY.

- Patented Apr. 1 5, 1941 PATENT oi' 'rlcs Application May 10, 1939,scram. 272,763 In GreatBx-itain March 17, 1938 11 Claims. (cl. 139-384)Q the edge of the outer band and about 2." further This inventionrelates to Venetian blind ladder webbing,'more particularly to a new andim-;

'- proved construction thereof. The present inventionis acontinuation-impart of vmy 'copending application Serial No. 203,584,illedApril 24, 1938, entitled Multiplewarp ladder web.

Venetian blind ladder web consists. of two 1 outer or body bands or'webs in between which are interwoven two generally narrower cross tapeswhich interweave for a distance with one body web forming a binding-inarea, then for a space as separate tape between the'two body webs; theninterweave for a simllar distance with the second body web and iourthlycross back to the first, bodyweb by means of short -15 free weftlesswarp threads or ends which require to be cut or snipped before thebodywebs can be separated and opened up to make the cross'tapesor strapsaccessible for the slats or laths; In-

order that the laths may. overlap it is necessary that there should betwo sets-of cross tapes-- (though maybe consisting of several sectionseach) woven in staggered relationship to each other, one towards, eachside of the body webs,

with a slight space between them. Occasionally 5.

they have met in the centre but they have never actually more thantouched each other.

This design of ladder webbing has never been altered since the inceptionof ladder weband it,

can be safely assumed that this staggering or forming one row of strapson each side of the outer bands was to enable each row of cross'- strapsto bind into one of the outer'bands, then weave a certain-length ofseparatecross-strap for-the lath to rest on, then binding into the.

' positioning in respectto each other and the other outer band and thenfor the strap warps to cross (without weft) back again to the first,

outer band completing the cycle without inter a ference from the otherstrap warps and to' give on (according tothe width of the lath employed)on the other side of the band would bea bind- -'ing-1n of the other rowof straps and in this way the designer was not only enabled to get theoverlap of the laths required but there was a space between the rows ofstraps in which the operating blind cord could work and be kept in itsplace by the staggered cross-straps. No

other way of construction of a Venetian blindladder web has ever beenthought possible and consequently this design of ladder web has beenuniversally used for about 100 years not only when loom woven, but alsowhen made by the earlier. hand methods. v v

' e main object of the present invention-is to produce ladder webbing inwhich the required blind 'lath' overlap is obtained, whilst formed withonly a single consolidated or composite row of crossfstraps, the usualtwo rows being merged into one width. A further object is to providesuch a webbing in which the cross-straps may extend across orsubstantially across the full width of the webbing, and if desired withthe usual -central' space in each full-width strap for the operatingcord, thereby increasing the strength and utility of the webbing.Alternatively, another object is to provide a webbing which,

'with only a-single row of narrow consolidated cross-straps, may benarrower, and thus cheaper to produce than the ordinary webbing,'especially when made with weftless cross-straps.

According to the present invention, however,

whilstthere remain two sets of cross tapes woven in the same staggeredrelationship, their body webs is less restricted; They may in whole orinpart intermingle (overlap, merge, come pound, superimpose, fuse) witheach other, one

overlapping of the laths. v V 40 above the other as it were. Preferablythey will If one places blind laths on a single row of" both becentrally spaced across the width of the .body .webs, or they may belocated slightly to blind would be valueless;

adding another row of cross-straps, placing one on one side and theother row on the-op- 5Q posite side, leaving a space between the two forthe operating cord to lie between. The binding or weaving-in of thesecross-strapsto. the outer bands was done in staggered formation, thatis,

such a construction of" The designer of Vene tian blinds therefore builtupv the ladder web by 7 one side of their respective ,body webs,overlapping inthe centre; In order that this whole or part overlappingmaytake place it is necessary v the usual cutting above described thecomposite ladder web separates in the usual way.

Application of this newprinciple of weaving will clearly permit eitherof narrower ladder web or wider cross tapes than has hitherto beenpossible-including the variety without weft in the binding of one row ofstraps would be near which a slight space is left in. the centre of thecross-strap warps so as to, permit of the cords being passed between thetwo ha'lv Actually, weaving a cross-strap is commenced beforecompleting'the preceding one,' and in this way a very simple, usefulandcheap construction of ladder webbing is provided; and when the lathstraps are made inthe'full width of the outer webbing (with a short gapfor the cords to operate) a web 01' double strength for the lath'to reston is produced and in the case of the weftless or part weftless strapsthe lath can be threaded half under andhalf over the weftless strapthreads to keep the laths from moving out of position. In the case ofweft- ,less straps two pieces of ladder webbing can be produced in onespace of a multiple loom with 4-tier rows of shuttles.

According to' the invention, the outer bands of thewebbing are eachformed as usual, but

instead of forming two rows of crom-straps spaced apart in staggered,formation as heretofore, they form one composite row, and each set isapplied in succession, that is to say, first one set of warps isconnected with one outer band for a distance (usually similar to thebindingin of the prior cross-straps), they then cross over to the otherouter band to form a crossstrap (with or without weft), and are thenbound into such other outer band fora like distance,

after whichthey cross directly back to the first o named band in theform of short free cross over warps for a repeat of the firstbinding-in. The other set of warps is applied in the same way, and inthe same line or path, starting with a short binding-in with thefirst-named outer band, then crossing over to the other outer band toform the next cross-strap, then being bound into such other outer band,and finally passing directly back to the first-named outer band as shortfree cross-over warps. The relationship between the two sets of warps issuch that whilst one set is in the middle of formation of a crossstrap,the other set is crossing over, through the first set as the short freecross over warps. That is to say, where each set of warp threads crossesover from one outer band to the other to form a cross-strap, the short,free warps of the next set of warps pass through them, and in such wayit is rendered possible for all the cross-strapsto lie in the one row.

- The bindings-in of each set of warps are spaced at a uniform distanceapart, and thus each alternate cross-strap lies centrally between andoverlaps the next preceding and next succeeding cross-straps formed bythe other set of warps, said overlapping giving the necessary overlapfor the blind laths.

The cross-strap warp connections; with the outer bands may vary inlength and may .be relatively short as in the original practice, or maybe longer as set forth in my earlierapplications Ser. Nos. 143,557 and67,809, and the connections will be efiected by interweaving the strapwarps with the outer bands by means of the weft of the bands, which willnot be affected by the interchange of the strap and band warps.

On removal of the webbing from the loom, the short free weftlesscross-over warp threads are cut away as usual. To reduce the cost ofsuch cutting away to a minimum the said free crossover warps are made asshort as possible, as for instance in my earlier application Ser. No.67,809, so that one snip of the scissors will sumce. However, theinvention may beapplied to ladder web having relatively long freecross-over warps.

, In the accompanying drawings, constitutinga part hereof'and in whichlike reference characters indicate like parts,

Fig. 1' is a longitudinal, cross-sectional view taken through a piece ofladder web made in accordance with the present invention, the spacing ofthe outer-bands being exaggerated for clearness;

Fig. 2 is a horizontal, cross-sectional view taken along the line 2-4 ofFig. l;

Fig. 3 is a top plan view of a modified form or ladder web;

Fig. 4 is a view similar to Fig. 3 showing a" slight further modifiedform;

Fig. 5 is a longitudinal, cross-sectional view of still anothermodification of the present invention;

Fig. 6 is a fragmentary horizontal cross-sectional view similar to Fig.2 of a modified form of the invention, wherein the cross-straps areformed with weft; and

Fig. 7 is a diagrammatic perspective view of the modification shown inFig. 6, the length of the free warps being greatly exaggerated for clearness.

An outer band i is woven with weft 2 and op- I posite and parallelthereto is a similar outer band 3 woven with weft 4. A cross-strapconsisting of warp threads only is held in outer band 3 at thebinding-in area. 8, the threads crossing over as shown at I to form abinding-inarea'l inouter band I. A cross-strap 9 then passes to theouter band 3 and the warps are woven into the same as shown at In toform a binding-in area and the warps continueas free cross-over threadsII, and the cycle is repeated.

In alignment therewith, a series of warp threads i2 form a cross-overfrom 3 to band I and are bound in as shown at H. In crossing over, the

warps 12 pass between-the warps 5 at H whereby there is an interlacingof the two sets of warp threads. From the binding-in ll there extends across-strap l5 which .interlaces with the free warps 1 at It. Theopposite end of cross-strap [5 forms the, binding-in I! on outer band 3.Free warps l8 pass through cross-strap 9 at I! and enter the outer band-I, forming a binding-in area. 20. Extending therefrom" is cross-strap 2I, which interlaces with-cross-over threads ll at 22, and the cycle isrepeated. I

Usually, the distance'between outer bands I and 3 is extremely'short'andpreferably they are woven in a contiguous manner so that the crossoverfrom warps l2, 1, II and II is extremely short. In order to open up theladder web, it is merely necessary to snip through these cross-overwarps. No trimming operations are ordinarily required.

' In Figures 1 and 2 the several cross-straps were shown as extendingpractically across the entire width'of the outer bands. Fig. 3 shows -aslight modification thereof in which there are no cross. strap elementsat the central portion 23 of the outerbands, leaving in effect twoidentical sections of consolidated cross-straps at the sides 24 and 25of said outer bands. The space 23 is in tended for the reception of acord constituting a part of a Venetian blind.

In Fig. 4 there is shown a still further modification of the structureof Fig. 3, wherein the pairs of cross-straps lie in the same planes. InFig, 4 there is a slight shifting of one of each 01' the pairs ofcross-straps. The binding-in 23 on side 24 of the upper outer band isequivalent to the binding-in ll of Figs. 1 to 3 inclusive. From sidebinding-in 28 across-strap passes to the oppostructijon. In actualpractice, such free warps site outer band, then forming a binding-in anda cross-over of free weft to the outer band I and then a binding-in 21,repeating the cycle. The second set of cross-straps on side l4 of outerband I is similarly formed, the bindings-in 28 and 29 being equivalentto those shown in Fig. 3.

However, on the side '25 of outer band I the binding-in 30 is not inalignment with binding-in- 26 but is slightly displaced. Then followsthe cross-strap to the opposite outer band, the binding-in thereon, thecross-over of free warps back n to outer band -I, and the'binding-in 3|.The

bindings-in 32 and 33 on outer band I are equivalent to similar elementson Fig.3.

.By reason of this construction, the two parts I of each cross-strap arenot in alignment, but are relatively displaced by a small amount. Thisenables a lath to be threaded between the two parts of the cross-strapwithoutany distortion of the threads. The amount of displacement willgenerally. be equivalent to the thickness of the lath.

In Fig. 5 there is shown a modification in which the binding-in areasare of substantially greater extent than shown in Fig. 1 forexample.Crossare extremely short. After the completion of theweaving, they aresnipped through in order to allow the ladder web to open up.

With the two rows of cross-straps consolidated, i. e brought'into line,they give the advantages in one row of the two separate and staggeredrows of cross-straps as regards overlap.

Furthermore, they allow of the outer bands being made to narrowerwidths, which for narrow and light laths is a desideratum.

The invention is, of course, applicable to wide webbing, and in suchconnection, the crossstraps may also be wide, and when weftless the',central warps may be omitted and'leave a space for the operating cord.In each case (narrow or wide webbing), the cross-straps may extend 1across or substantially across the full width of 'the webbing, or, inthe case of a row with the central space 2 one half width may extend toone selvedge of the webbing and the other half width-extend to the otherselvedge of the webbing.

-When the composite row of cross-straps is divided, the laths may bethreaded between the two portions of each strap to prevent accidentaldisplacement, say by wind. Although preferring threads 44 in outer band2 forms the cross-strap 45, along binding-in 45 in band I, a cross-over41, and a long binding-in 48. in band 2. All this isin accordance withmy co-pending application above referred to. I

In addition, there is provided a second series of cross-straps whichinterlace with the first series in a manner similar to the descriptionin connection with Figs. 1 and 2. avoid confusion, the second series ofcross-straps have been indicated only diagrammatically in-Fig;

However, in order to that the cross-straps in each row shall completely'overlie each other transversely, the crossstraps formed by one set ofwarps may only partly overlie the cross-straps formed by the other setof warps. c

It should 'nowbeseen that the main feature of the invention is themerging of the two sets of cross-straps into one row, which ismade'possible by the short, free portions of one of the sets of warpspassing through the cross-straps or of the other set of warps, saidshort, free portions being afterwards cut away.

By this invention the webbing can, if desired, be made to proportions inwidth whlchis not possible with the ordinary webbing with thecross-straps intwo' rows and staggered. By virtue of the cross-strapsbeing further away from and central to the outer bands, they will(especially when weftless) .be less visible than they 5. There is, forexample, shown a binding-in .49 on outer band I, a cross-over 50, thethreads in- I terlacing with those ofcross-strap 45, and thenabinding-in 52 on band 2.

A cross-strap '54 interlaces at 55 with cross-over threads 35 and isbound into band I at 55. A cross-over I8 thg'e from interlaces at 51with cross-strap 4| and forms a bindingin 58 on-band 2. This diagram-fmatic showing indicates long binding-in areas of the cross-straps inboth sets. However, the bind ings-in may be short in accordance withpreviously known practice.

Inthe above description of Figs. 1 to' 5 inclu-.'

sive, the cross-straps were of the weftless type. However, it ispossible to form such cross-straps wc'puld'be in the knownordinarywebbing. Al-

though the cross-straps will preferably be 'weftless or partly weftless,they may be composed wholly or warp and weft and the short free,cross-over warps pass through them (even though. woven) and beafterwards cut away. Such strap weft, after forming or partly forming across-strap, may be bound to the band, or

pass directly to the next cross-strap.

9 'When the cross-straps are entirely weftless,. two complete webbingsmaybe produced simultaneously'in a single loom slot, (using four tiersof shuttles), thus increasing production and also reducing the cost ofproduction.

' In place of warps, a series of lengths of cord,

. straps.

on outer band 2. In Fig. 7 these free warps have been shown as greatlyexaggerated in length in order to clearly illustrate the con- Although Ihave described my invention, setting forth several speciflc embodimentsthereof,

the inventionis not limited to the detailsv here shown .and described.,By the various modifications described herein it was intended to showthe many forms which the present invention may take, it being essentialfor the present purposes that the free warps for one set of'crossstrapspass through the cross-straps for the other set. Therefore. my inventionis to be broadly construed and to be limited only by the claims appendedhereto.

What I claim is:

1. In ladder web including two outer bands and a series of cross-strapstherebetween at spaced intervals, the improvement which comprises atleast two sets of cross-strap warp threads, each set iormingsuccessively a binding--/ in on one outer band, across-strap, abinding-in on the opposite outer band and a free warp crossover, eachset passing through the other at intervals, the distance betweenadjacent crossstraps being less than the length of said crossstraps.

2. In ladder web including two outer bands and and a series ofcross-straps therebetween at .spaced intervals, the improvement whichcoma series of cross-straps therebetween at spaced intervals, theimprovement which comprises at least two sets of cross-strap warpthreads, each set forming successively a binding-in on one outer band, across-strap, a binding-in on the opposite outer band and a tree warpcross-over,

each set passing through the other at intervals,

the two sets of cross-straps so formed being in alignment,the distancebetween adjacent crossstraps being less than the length of saidcrossstraps. v

3. In ladder web including two outer bands and a series of cross-strapstherebetweenat spaced intervals, the improvement which comprises twosets of cross-strap warp threads, each set forming successively abinding-in on one outer band, a cross-strap, a binding-in on theopposite outer band and a free warp cross-over,

each set passing through the other at intervals,

the two sets 01' cross-straps so formed being in alignment, and eachcross-strap'being divided centrally to provide a ,space for an operatingcord, the distance between adjacent cross-straps being less than thelength 01. said cross-straps.

8. In ladder web including two outer bands and a series of cross-strapstherebetween at spaced intervals, the improvement which comprises twosets of cross strap warp threads, each prises at least two sets ofcross-strap warp threads, each set .forming successively a bindingin onone outer band, a cross-strap, a binding-in on the opposite outer bandand a free warp cross-over, each set passing through the other atintervals, the two sets of cross-straps so formed being in alignment,said cross-over being snipped through, the distance between adjacentcrossstraps being less than the length 01' said crossstraps. I

4.'In ladder web including two outer bands and a series of cross-strapstherebetween at spaced intervals, the improvement which comprisesatleast two sets of cross-strap warp threads, each set formingsuccessively a bindingin on one outer band, a cross-strap,'a binding-inon the opposite outer band anda free warp crossover, each set passingthrough the other at intervals, the two sets of cross-straps so formedbeing in alignment, each of said cross-straps being woven with weft atleast in part, the distance between adjacent cross-straps being lessthan the length of said cross-straps.

5. In ladder web including two outer bands and a series ofcross-straps'therebetween at spaced intervals, the improvement whichcomprises at least two sets of cross-strap warp threads, each setforming successively a binding-in on one outer band, a cross-strap, abinding-in on the opposite outer band and a free warp cross-over, eachset passing through the other at intervals, 9

set 'iorming successively a binding-4n on one outer band, a cross-strap,a binding-in on the opposite outer band and a free warp cross-over, eachset passing through the other at intervals, the two sets or cross-strapsso formed being in alignment, each cross-strap being divided cen trallyand the binding-in of one-half width of each strap being in advance ofthe binding-in oi the other half width of such cross-strap, the distancebetween adjacent cross-straps being less than the length of saidcross-straps,

9. In laddel web including two outer bands and a series of cross-strapstherebetween at spaced intervals, the improvement which comprises twosets of cross-strap warp threads, each set forming successively abinding-in on one outer band, a cross-strap, a binding-in on theopposite outer band and a free warp cross-over, each set passing throughthe other at intervals, the two sets of cross-straps so formed being inalignment, each cross-strap being divided centrally and the binding-inof one-half width of each strap being in advance of the binding-in ofthe other half width of such cross-strap to an extent equal to thethickness of a lath, the distance between adjacent cross-straps beingless than the length or said cross-straps.

10. In ladder web including two outer bands and a series of cross-strapstherebetween at spaced intervals, the improvement which comprises atleast two sets of cross-strap warp threads forming two alternating setsof crossstraps, both 01 said sets of cross-straps being in substantialalignment, the distance between ad- -jacent cross-straps being less thanthe length of said cross-straps.

11. In ladder web' including two outer bands and a series ofcross-straps therebetween at spaced intervals, the improvement whichcomprises at least two sets of cross-strap warp threads forming twoalternating sets of crossstraps, both of said sets of cross-strapsoverlapping at least in part, the distance between adjacent cross-strapsbeing less than the length of said cross-straps.

GEORGE FREDERICK FRENCH.

